Lightweight Container Base

ABSTRACT

A container defining a longitudinal axis and a transverse direction that is transverse with respect to the longitudinal axis. The container includes a finish and a sidewall portion extending from the finish. A plurality of ribs are defined by the sidewall. A base portion extends from the sidewall portion and encloses the sidewall portion to form a volume therein for retaining a commodity. The base portion has a contact surface for supporting the container. A plurality of straps extend radially along the base portion away from the longitudinal axis in the transverse direction, each one of the straps defines a strap surface that is closer to the finish than the contact surface. The plurality of ribs and the base portion are configured to place the container in a state of hydraulic charge-up when top load is applied to the container after the container is filled.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/581,855 filed Apr. 28, 2017, which is a continuation-in-part of U.S.patent application Ser. No. 14/465,494 filed Aug. 21, 2014 (issued asU.S. Pat. No. 9,694,930 on Jul. 4, 2017), which is acontinuation-in-part of PCT International Application No.PCT/US2013/057708 filed Aug. 30, 2013, which is a continuation-in-partof PCT International Application No. PCT/US2012/053367 filed Aug. 31,2012, which claims the benefit of U.S. Provisional Application No.61/529,285, filed on Aug. 31, 2011. The entire disclosures of each ofthe above-referenced applications are incorporated herein by reference.

FIELD

This disclosure generally relates to containers for retaining acommodity, such as a solid or liquid commodity. More specifically, thisdisclosure relates to a container having an optimized base design toprovide a balanced vacuum and pressure response, while minimizingcontainer weight.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art. This section alsoprovides a general summary of the disclosure, and is not a comprehensivedisclosure of its full scope or all of its features.

As a result of environmental and other concerns, plastic containers,more specifically polyester and even more specifically polyethyleneterephthalate (PET) containers are now being used more than ever topackage numerous commodities previously supplied in glass containers.Manufacturers and fillers, as well as consumers, have recognized thatPET containers are lightweight, inexpensive, recyclable andmanufacturable in large quantities.

Blow-molded plastic containers have become commonplace in packagingnumerous commodities. PET is a crystallizable polymer, meaning that itis available in an amorphous form or a semi-crystalline form. Theability of a PET container to maintain its material integrity relates tothe percentage of the PET container in crystalline form, also known asthe “crystallinity” of the PET container. The following equation definesthe percentage of crystallinity as a volume fraction:

${\% \mspace{14mu} {Crystallinity}} = {\left( \frac{\rho - \rho_{a}}{\rho_{c} - \rho_{a}} \right) \times 100}$

where ρ is the density of the PET material; ρa is the density of pureamorphous PET material (1.333 g/cc); and ρc is the density of purecrystalline material (1.455 g/cc).

Container manufacturers use mechanical processing and thermal processingto increase the PET polymer crystallinity of a container. Mechanicalprocessing involves orienting the amorphous material to achieve strainhardening. This processing commonly involves stretching an injectionmolded PET preform along a longitudinal axis and expanding the PETpreform along a transverse or radial axis to form a PET container. Thecombination promotes what manufacturers define as biaxial orientation ofthe molecular structure in the container. Manufacturers of PETcontainers currently use mechanical processing to produce PET containershaving approximately 20% crystallinity in the container's sidewall.

Thermal processing involves heating the material (either amorphous orsemi-crystalline) to promote crystal growth. On amorphous material,thermal processing of PET material results in a spherulitic morphologythat interferes with the transmission of light. In other words, theresulting crystalline material is opaque, and thus, generallyundesirable. Used after mechanical processing, however, thermalprocessing results in higher crystallinity and excellent clarity forthose portions of the container having biaxial molecular orientation.The thermal processing of an oriented PET container, which is known asheat setting, typically includes blow molding a PET preform against amold heated to a temperature of approximately 250° F.-350° F.(approximately 121° C.-177° C.), and holding the blown container againstthe heated mold for approximately two (2) to five (5) seconds.Manufacturers of PET juice bottles, which must be hot-filled atapproximately 185° F. (85° C.), currently use heat setting to producePET bottles having an overall crystallinity in the range ofapproximately 25%-35%.

Unfortunately, with some applications, as PET containers for hot fillapplications become lighter in material weight (aka container gramweight), it becomes increasingly difficult to create functional designsthat can simultaneously resist fill pressures, absorb vacuum pressures,and withstand top loading forces. According to the principles of thepresent teachings, the problem of expansion under the pressure caused bythe hot fill process is improved by creating unique vacuum/label panelgeometry that resists expansion, maintains shape, and shrinks back toapproximately the original starting volume due to vacuum generatedduring the product cooling phase.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

SUMMARY

The present teachings provide for a container defining a longitudinalaxis and a transverse direction that is transverse with respect to thelongitudinal axis. The container includes a finish and a sidewallportion extending from the finish. A plurality of ribs are defined bythe sidewall portion. A base portion extends from the sidewall portionand encloses the sidewall portion to form a volume therein for retaininga commodity. The base portion has a contact surface for supporting thecontainer. A plurality of straps extend radially along the base portionaway from the longitudinal axis in the transverse direction, each one ofthe straps defines a strap surface that is closer to the finish than thecontact surface. The plurality of ribs and the base portion areconfigured to place the container in a state of hydraulic charge-up whentop load is applied to the container after the container is filled.

The present teachings also provide for a container defining alongitudinal axis and a transverse direction that is transverse withrespect to the longitudinal axis. The container includes a finish, asidewall portion, a base portion, a plurality of straps, a plurality ofrib members, and a central portion. The sidewall portion extends fromthe finish. A plurality of horizontal side ribs are defined by thesidewall. The base portion extends from the sidewall portion andencloses the sidewall portion to form a volume therein for retaining acommodity. The base portion has a contact surface for supporting thecontainer. The plurality of straps extend radially along the baseportion away from the longitudinal axis in the transverse direction.Each one of the straps defines a strap surface that is closer to thefinish than the contact surface. The plurality of base rib members arerecessed within the base portion. Each one of the plurality of base ribmembers is between two of the plurality of straps. A central pushupportion is at an axial center of the base portion. The longitudinal axisextends through the central pushup portion. The plurality of horizontalside ribs and the base portion are configured to place the container ina state of hydraulic charge-up when top load is applied to the containerafter the container is filled.

The present teachings further provide for a container defining alongitudinal axis and a transverse direction that is transverse withrespect to the longitudinal axis. The container includes a finish, asidewall portion, a base portion, a plurality of straps, a plurality ofrib members, and a central pushup portion. The sidewall portion extendsfrom the finish. A plurality of horizontal side ribs are defined by thesidewall portion. The base portion extends from the sidewall portion andencloses the sidewall portion to form a volume therein for retaining acommodity. The base portion has a contact surface for supporting thecontainer. The plurality of straps extend radially along the baseportion away from the longitudinal axis in the transverse direction.Each one of the straps defines a strap surface that is closer to thefinish than the contact surface. A plurality of base rib members arerecessed within the base portion. Each one of the plurality of base ribmembers is between two of the plurality of straps. The central pushupportion is at an axial center of the base portion. The longitudinal axisextends through the central pushup portion. Each one of the plurality ofstraps is at least partially aligned with one of the base rib members inthe transverse direction on opposite sides of the longitudinal axis. Theplurality of horizontal side ribs and the base portion are configured toplace the container in a state of hydraulic charge-up when top load isapplied to the container after the container is filled. The plurality ofhorizontal side ribs collapse upon application of top load, and movementof the base portion is constrained by a standing surface, therebycausing fluid within the volume of the container to reach anincompressible state and resist deformation of the container.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIGS. 1-5 are views illustrating exemplary embodiments of a containerwith various features of the present teachings, wherein FIG. 1 is aperspective view, FIG. 2 is a side view, FIG. 3 is a front view, FIG. 4is a bottom view, and FIG. 5 is a section view taken along the line 5-5of FIG. 4;

FIGS. 6-9 are views illustrating additional exemplary embodiments of acontainer with various features of the present teachings, wherein FIG. 6is a perspective view, FIG. 7 is a side view, FIG. 8 is a bottom view,and FIG. 9 is a section view taken along the line 9-9 of FIG. 8;

FIGS. 10-13 are views illustrating additional exemplary embodiments of acontainer with various features of the present teachings, wherein FIG.10 is a perspective view, FIG. 11 is a side view, FIG. 12 is a bottomview, and FIG. 13 is a section view taken along the line 13-13 of FIG.12;

FIGS. 14-17 are views illustrating additional exemplary embodiments of acontainer with various features of the present teachings, wherein FIG.14 is a perspective view, FIG. 15 is a side view, FIG. 16 is a bottomview, and FIG. 17 is a section view taken along the line 17-17 of FIG.16;

FIGS. 18 and 19 are views illustrating additional exemplary embodimentsof a container with various features of the present teachings, whereinFIG. 18 is a bottom view and FIG. 19 is a section view taken along theline 19-19 of FIG. 18;

FIGS. 20 and 21 are views illustrating additional exemplary embodimentsof a container with various features of the present teachings, whereinFIG. 20 is a bottom view and FIG. 21 is a section view taken along theline 21-21 of FIG. 20;

FIGS. 22 and 23 are views illustrating additional exemplary embodimentsof a container with various features of the present teachings, whereinFIG. 22 is a bottom view and FIG. 23 is a section view taken along theline 23-23 of FIG. 22;

FIGS. 24 and 25 are views illustrating additional exemplary embodimentsof a container with various features of the present teachings, whereinFIG. 24 is a bottom view and FIG. 25 is a section view taken along theline 25-25 of FIG. 24;

FIGS. 26A and 26B are section and side views, respectively, of a baseportion of a container according to additional exemplary embodiments ofthe present disclosure;

FIGS. 27A and 27B are section and side views, respectively, of a baseportion of a container according to additional exemplary embodiments ofthe present disclosure;

FIGS. 28A and 28B are front and side views, respectively, of a generallyrectangular container according to additional exemplary embodiments ofthe present disclosure;

FIGS. 29A and 29B are perspective and bottom views, respectively, of agenerally cylindrical container according to additional exemplaryembodiments of the present disclosure;

FIGS. 30A and 30B are perspective and bottom views, respectively, of agenerally cylindrical container according to additional exemplaryembodiments of the present disclosure;

FIGS. 31A and 31B are views of additional exemplary embodiments of acontainer according to the present teachings, wherein FIG. 31A is abottom view and FIG. 31B is a section view taken along the line 31B-31Bof FIG. 31A;

FIG. 32 is a perspective view of a mold system suitable for molding thecontainer of the present disclosure;

FIGS. 33A-33C is a series of graphs illustrating the relationshipbetween strap inclination angle and volume displacement, the number ofstraps and radial strength, the strap peak angle and volumedisplacement, and between dimensions of a strap of the container and avolume displacement of a hot-filled container;

FIG. 34 is a schematic section view of a container showing variouscurving surfaces of a central pushup portion thereof;

FIGS. 35A-35D are schematic bottom views of a central pushup portion ofa container according to teachings of the present disclosure;

FIG. 36 is a schematic section view of a container showing variousshapes for straps thereof;

FIGS. 37-39 are schematic bottom views of the container showing variousshapes for straps thereof;

FIGS. 40-45 are views illustrating additional exemplary embodiments of acontainer with various features of the present teachings, wherein FIG.40 is a side view, FIG. 41 is a perspective view, FIG. 42 is a bottomview, FIG. 43 is a section view taken along line 43-43 of FIG. 42, andFIGS. 44 and 45 are schematics of a base on the container;

FIG. 46 is a graph illustrating relationship between outward strapradius and volume displacement of containers according to the presentteachings;

FIG. 47 is a graph illustrating relationship between base clearance andvolume displacement of containers according to the present teachings;

FIG. 48 is a graph illustrating relationship between standing baseradius and volume displacement of containers according to the presentteachings;

FIG. 49 is a graph illustrating relationship between inward foot radiusand volume displacement of containers according to the presentteachings;

FIG. 50 is a graph illustrating relationship between foot separation andvolume displacement of containers according to the present teachings;

FIG. 51 is a graph illustrating relationship between an outer strapradius and an inner foot radius of containers according to the presentteachings;

FIG. 52A is a side view of another container according to the presentteachings, the container in an as-blown, pre-filled configuration;

FIG. 52B is a side view of the container of FIG. 52A after the containerhas been hot-filled and has cooled;

FIG. 52C is a side view of the filled container of FIG. 52B subject to atop load pressure;

FIG. 52D is a side view of the filled container of FIG. 52C subject tofurther top load pressure;

FIG. 53 is a graph illustrating base volume change versus pressure of anexemplary container according to the present teachings;

FIG. 54 is a graph of filled, capped, and cooled top load versusdisplacement of an exemplary container according to the presentteachings;

FIG. 55 is a graph illustrating volume change versus gauge pressure ofan exemplary container according to the present teachings;

FIG. 56 is a graph illustrating body volume change versus gauge pressureof an exemplary container according to the present teachings;

FIG. 57 is a graph illustrating base volume change versus gauge pressureof an exemplary container according to the present teachings;

FIG. 58A is a plan view of a container base in accordance with thepresent teachings;

FIG. 58B is a cross-sectional view taken along line 58B-58B of FIG. 58A;

FIG. 59A is a plan view of an additional container base according to thepresent teachings;

FIG. 59B is a cross-sectional view taken along line 59B-59B of FIG. 59A;

FIG. 59C is a cross-sectional view taken along line 59C-59C of FIG. 59A;

FIG. 59D is a cross-sectional view taken along line 59D-59D of FIG. 59A;and

FIG. 60A, FIG. 60B, FIG. 60C, FIG. 60D, and FIG. 60E illustrateproperties of an additional container in accordance with the presentteachings.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings. Example embodiments are provided so that thisdisclosure will be thorough, and will fully convey the scope to thosewho are skilled in the art. Numerous specific details are set forth suchas examples of specific components, devices, and methods, to provide athorough understanding of embodiments of the present disclosure. It willbe apparent to those skilled in the art that specific details need notbe employed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on”, “engaged to”,“connected to” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto”, “directly connected to” or “directly coupled to” another element orlayer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”,“lower”, “above”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

This disclosure provides for a container being made of PET andincorporating a base design having an optimized size and shape thatresists container loading and pressures caused by hot fill pressure andresultant vacuum, and helps maintain container shape and response.

It should be appreciated that the size and specific configuration of thecontainer may not be particularly limiting and, thus, the principles ofthe present teachings can be applicable to a wide variety of PETcontainer shapes. Therefore, it should be recognized that variations canexist in the present embodiments. That is, it should be appreciated thatthe teachings of the present disclosure can be used in a wide variety ofcontainers, including rectangular, round, oval, squeezable, recyclable,and the like.

As shown in FIGS. 1-5, the present teachings provide a plastic, e.g.polyethylene terephthalate (PET), container generally indicated at 10.The exemplary container 10 can be substantially elongated when viewedfrom a side and generally cylindrical when viewed from above and/orrectangular in throughout or in cross-sections (which will be discussedin greater detail herein). Those of ordinary skill in the art wouldappreciate that the following teachings of the present disclosure areapplicable to other containers, such as rectangular, triangular,pentagonal, hexagonal, octagonal, polygonal, or square shapedcontainers, which may have different dimensions and volume capacities.It is also contemplated that other modifications can be made dependingon the specific application and environmental requirements.

In some embodiments, container 10 has been designed to retain acommodity. The commodity may be in any form such as a solid orsemi-solid product. In one example, a commodity may be introduced intothe container during a thermal process, typically a hot-fill process.For hot-fill bottling applications, bottlers generally fill thecontainer 10 with a product at an elevated temperature betweenapproximately 155° F. to 205° F. (approximately 68° C. to 96° C.) andseal the container 10 with a closure before cooling. In addition, theplastic container 10 may be suitable for other high-temperaturepasteurization or retort filling processes or other thermal processes aswell. In another example, the commodity may be introduced into thecontainer under ambient temperatures.

As shown in FIGS. 1-5, the exemplary plastic container 10 according tothe present teachings defines a body 12, and includes an upper portion14 having a cylindrical sidewall 18 forming a finish 20. Integrallyformed with the finish 20 and extending downward therefrom is a shoulderportion 22. The shoulder portion 22 merges into and provides atransition between the finish 20 and a sidewall portion 24. The sidewallportion 24 extends downward from the shoulder portion 22 to a baseportion 28 having a base 30. In some embodiments, sidewall portion 24can extend down and nearly abut base 30, thereby minimizing the overallarea of base portion 28 such that there is not a discernable baseportion 28 when exemplary container 10 is uprightly-placed on a surface.

The exemplary container 10 may also have a neck 23. The neck 23 may havean extremely short height, that is, becoming a short extension from thefinish 20, or an elongated height, extending between the finish 20 andthe shoulder portion 22. The upper portion 14 can define an opening forfilling and dispensing of a commodity stored therein. The container canbe a beverage container; however, it should be appreciated thatcontainers having different shapes, such as sidewalls and openings, canbe made according to the principles of the present teachings.

The finish 20 of the exemplary plastic container 10 may include athreaded region 46 having threads 48, a lower sealing ridge 50, and asupport ring 51. The threaded region provides a means for attachment ofa similarly threaded closure or cap (not shown). Alternatives mayinclude other suitable devices that engage the finish 20 of theexemplary plastic container 10, such as a press-fit or snap-fit cap forexample. Accordingly, the closure or cap engages the finish 20 topreferably provide a hermetical seal of the exemplary plastic container10. The closure or cap is preferably of a plastic or metal materialconventional to the closure industry and suitable for subsequent thermalprocessing.

In some embodiments, the container 10 can comprise a lightweight baseconfiguration 100 generally formed in base portion 28. Baseconfiguration 100 can comprise any one of a number of features thatfacilitate vacuum response, improve structural integrity, minimizecontainer weight, and/or improve overall performance of container 10. Asdiscussed herein, base configuration 100 can be used in connection withany container shape, however, by way of illustration, containers havingrectangular and cylindrical cross-sections will be examined. The baseportion 28 functions to close off the bottom portion of the plasticcontainer 10 to retain a commodity in the container 10. FIGS. 1-31Billustrate a variety of base configurations 100 and base portions 28 aswell, as will be discussed.

Referring back to FIGS. 1-5, the base portion 28 of the plasticcontainer 10, which extends inward from the body 12, can comprise one ormore contact surfaces 134 and a central portion 136. In someembodiments, the contact surface(s) 134 is the area of the base portion28 that contacts a support surface (e.g. shelf, counter, and the like)that in turn supports the container 10. As such, the contact surface 134may be a flat surface (an individual flat surface or a collection ofseparately spaced flat surfaces that each lie within a common plane. Thecontact surface 134 can also be a line of contact generallycircumscribing, continuously or intermittently, the base portion 28.

In the embodiments of FIGS. 1-5, the base portion 28 includes fourcontact surfaces 134, which are spaced away from each other about thelongitudinal axis 150 of the container 10. Also, in the embodimentsshown, the contact surfaces 134 are arranged at the corners of the baseportion 28. However, it will be appreciated that there can be any numberof contact surfaces 134 and the contact surfaces 134 can be disposed inany suitable position.

The base portion 28 can further include a central pushup portion 140,which is most clearly illustrated in FIGS. 4 and 5. The central pushupportion 140 can be centrally located (i.e., substantially centered onthe longitudinal axis 150). The central pushup portion 140 can extendgenerally toward the finish 20. In some embodiments, the central pushupportion 140, when viewed in cross section (FIG. 5), is generally in theshape of a truncated cone having a top surface 146 that is generallyparallel to the support surfaces 134. The pushup portion 140 can alsoinclude side surfaces 148 that slope upward toward the centrallongitudinal axis 150 of the container 10. The side surfaces 148 can befrusto-conic or can include a plurality of planar surfaces that arearranged in series about the axis 150.

Other shapes of the central pushup portion 140 are within the scope ofthe present disclosure. For instance, as shown in FIG. 13, the pushupportion 140 can be partially frusto-conic and partially cylindrical.Also, as shown in FIGS. 17, 23, and 25, the pushup portion 140 can begenerally frusto-conic with a plurality of ribs 171 that extend at anangle along the side surface 148 at equal spacing about the axis 150.Moreover, as shown in FIGS. 19 and 21, the pushup portion 140 can beannular, so that a depending frusto-conic projects exteriorly along theaxis 150. FIGS. 35A-35D show additional shapes for the pushup portion140 (in respective bottom views of the container 10). For instance, thetop surface 146 can be defined by a plurality of convexly curved linesthat are arranged in series about the axis (FIG. 35A), an octagon orother polygon (FIG. 35B), alternating convexly and concavely curvedlines (FIG. 35C), and a plurality of concavely curved lines (FIG. 35D).The side surface(s) 148 can project therefrom to have a correspondingshape.

As shown in FIG. 34, the top surface 146 and/or the side surface(s) 148can have a concave and/or convex contour. For instance, the top surface146 can have a concave curvature (indicated at 146″) or a convexcurvature (indicated at 146″). Additionally, the side surface 148 canhave a concave curvature (indicated at 148″), a convex curvature(indicated at 148″), or a S-shaped combination concave and convexcurvature (indicated at 148″). This curvature can be present when thecontainer 10 is empty. Also, the curvature can be the result ofdeformation due to vacuum loads inside the container 10.

The side surface 148 can also be stepped in some embodiments. Also, theside surface 148 can include ribs, convex or concave dimples, or rings.

The exact shape of the central pushup 140 can vary greatly depending onvarious design criteria. For additional details about suitable shapes ofcentral pushup 140, attention should be directed to commonly-assignedU.S. patent application Ser. No. 12/847,050, which published as U.S.Patent Publication No. 2011/0017700, which was filed on Jul. 30, 2010,and which is incorporated herein by reference in its entirety.

The central pushup 140 is generally where the preform gate is capturedin the mold when the container 10 is blow molded. Located within the topsurface 146 is the sub-portion of the base portion 28, which typicallyincludes polymer material that is not substantially molecularlyoriented.

The container 10 can be hot-filled and, upon cooling, a vacuum in thecontainer 10 can cause the central pushup 140 to move (e.g., along theaxis 150, etc.) to thereby decrease the internal volume of the container10. The central pushup 140 can also resiliently bend, flex, deform, orotherwise move in response to these vacuum forces. For instance, the topsurface 146 can be flat or can convexly curve without the vacuum forces,but the vacuum forces can draw the top surface 146 upward to have aconcave curvature as shown in FIG. 34. Likewise, the side surfaces 148can deform due to the vacuum to be concave and/or convex as shown inFIG. 34. Thus, the central pushup 140 can be an important component ofvacuum performance of the container 10 (i.e., the ability of thecontainer 10 to absorb these vacuum forces without losing its ability tocontain the commodity, withstand top loading, etc.)

Various factors have been found for the base portion 28 that can enhancesuch vacuum performance. In conventional applications, it has been foundthat material can be trapped or otherwise urged into the pushup portionof the base. The amount of material in these conventional applicationsis often more than is required for loading and/or vacuum response and,thus, represents unused material that adds to container weight and cost.This can be overcome by tailoring the pushup diameter (or width in termsof non-conical applications) and/or height to achieve improved loadingand/or vacuum response from thinner materials. That is, by maximizingthe performance of the central pushup 140, the remaining containerportions need not be designed to withstand a greater portion of theloading and vacuum forces, thereby enabling the overall container to bemade lighter at a reduced cost. When all portions of the container aremade to perform more efficiently, the container can be more finelydesigned and manufactured.

To this end, it has been found that by reducing the diameter of centralpushup 140 and increasing the pushup height thereof, the material can bestretched more for improved performance. With reference to FIG. 5, eachcontainer 10 having pushup 140 defines several dimensions, including apushup width Wp (which is generally a diameter of the entrance ofcentral pushup 140), a pushup height Hp (which is generally a heightfrom the contact surface 134 to the top surface 146), and an overallbase width Wb (which is generally a diameter or width of base portion 28of container 10). Based on performance testing, it has been found thatrelationships exist between these dimensions that lead to enhancedperformance. Specifically, it has been found that a ratio of pushupheight Hp to pushup width Wp of about 1:1.3 to about 1:1.4 is desirable(although ratios of about 1:1.0 to about 1:1.6 and ratios of about 1:1.0to about 1:1.7 can be used). Moreover, a ratio of pushup width Wp tooverall base width Wb of about 1:2.9 to about 1:3.1 is desirable(although ratios of about 1:2.9 to about 1:3.1 and ratios of about 1:1.0to about 1:4.0 can be used). Moreover, in some embodiments, centralpushup 140 can define a major diameter (e.g. typically equalapproximately to the pushup width Wp or the diameter at the lowermostportion of central pushup 140). The central pushup 40 can further definea minor diameter (e.g. typically equal to the diameter of the topsurface 146 or the width at the uppermost portion of central pushup140). The combination of this major diameter and minor diameter canresult in the formation of a truncated conical shape. Moreover, in someembodiments, the surface of this truncated conical shape can define adraft angle of less than about 45 degrees relative to centrallongitudinal axis 150. It has been found that this major diameter orwidth can be less than about 50 mm and the minor diameter or width canbe greater than about 5 mm, separately or in combination.

In some embodiments shown in FIGS. 8 and 9, the container 10 can includean inversion ring 142. The inversion ring 142 can have a radius that islarger than the central pushup 140, and the inversion ring 142 cancompletely surround and circumscribe the central pushup 140. In theposition shown in FIGS. 8 and 9 and under certain internal vacuumforces, the inversion ring 142 can be drawn upward along the axis 150away from the plane defined by the contact surface 134. However, whenthe container 10 is formed, the inversion ring 142 can protrudeoutwardly away from the plane defined by the contact surface 134. Thetransition between the central pushup 140 and the adjacent inversionring 142 can be rapid in order to promote as much orientation as nearthe central pushup 140 as possible. This serves primarily to ensure aminimal wall thickness for the inversion ring 142, in particular at thecontact surface 134 of the base portion 28. At a point along itscircumferential shape, the inversion ring 142 may alternatively featurea small indentation, not illustrated but well known in the art, suitablefor receiving a pawl that facilitates container rotation about thecentral longitudinal axis 150 during a labeling operation.

In some embodiments, as illustrated throughout the figures and notablyin FIGS. 28A-31A, the container 10 can further comprise one or morestraps 170 formed along and/or within base portion 28. As can be seenthroughout FIGS. 1-25, straps 170 can be formed as recessed portionsthat are visible from the side of container 10. That is, straps 170 canbe formed such that they define a surface (i.e., a strap surface 173that defines a strap axis of the respective strap 170). The strapsurface 173 can be offset at a strap distance Ds (FIG. 2) from contactsurface(s) 134 in the Z-axis (generally along central longitudinal axis150 of container 10). In some embodiments, this offset Ds between straps170 and contact surface 134 can be in the range of about 5 mm to about25 mm. Also, the strap surface 173 can extend transverse to the axis 150to terminate adjacent the sidewall portion 24. The periphery of thestraps 170 can contour so as to transition into the sidewall portion 24and/or the contact surfaces 134.

At least a portion of the strap surface 173 can extend substantiallyparallel to the plane of the contact surfaces 134 as shown in FIGS. 1-4.Also, in some embodiments illustrated in FIGS. 10-12, at least a portionof the strap surface 173 can be partially inclined at a positive anglerelative to the contact surface 134. The angle can be less than 15degrees in some embodiments. The angle can be greater than 15 degrees inother embodiments.

FIG. 36 shows various shapes that the straps 170 can have. For instance,the straps can concavely contour toward the interior of the container 10as the strap extends in the transverse direction (indicated at 170′).The strap can also convexly contour away from the interior as the strapextends in the transverse direction (indicated at 170″). Moreover, thestrap can have one or more steps the along the axis 150 as the strapextends in the transverse direction (indicated at 170′″).

FIGS. 37-39 show how the straps can be shaped in plan view (viewed alongthe longitudinal axis 150). For instance, the strap can have asinusoidal curvature in the transverse direction (indicated at 170″″ inFIG. 37). The strap can also include steps as the strap extends in thetransverse direction (indicated at 170 in FIG. 37). The width of thestrap can increase (shown on the right side of FIG. 37) or can decrease(shown on the left side of FIG. 37) as the strap extends transverselyaway from the longitudinal axis 150. Moreover, the strap can smoothlytaper in the transverse direction (indicated at 170″″″ in FIG. 39). Thewidth of the strap can either increase (top and bottom straps of FIG.39) or decrease (left and right straps of FIG. 39) as the strap extendsaway from the longitudinal axis 150. Additionally, the straps canradiate from the longitudinal axis 150 and can each have a substantiallycommon curvature in the transverse direction to resemble a pinwheel(indicated at 170′″″″ in FIG. 38). Other shapes, curvatures, etc. arealso within the scope of the present disclosure.

The shape, dimensions, and other features of the straps 170 can dependupon container shape, styling, and performance criteria. Moreover, itshould be recognized that the offset (along the axis 15) of one strap170 can differ from the offset of another strap 170 on a singlecontainer to provide a tuned or otherwise varied load response profile.Straps 170 can interrupt contact surface 134, thereby resulting in aplurality of contact surfaces 134 (also known as a footed or segmentedstanding surface). Because of the offset nature of straps 170 and theirassociate shape, size, and inclination (as will be discussed), straps170 is visible from a side view orientation and formable via simplifiedmold systems (as will be discussed).

It has been found that the use of straps 170 can serve to reduce theoverall material weight needed within base portion 28, compared toconventional container designs, while simultaneously providingsufficient and comparable vacuum performance. In other words, straps 170have permitted containers according to the principles of the presentteachings to achieve and/or exceed performance criteria of conventionalcontainers while also minimizing container weight and associated costs.

In some embodiments, container 10 can include at least one strap 170disposed in base portion 28. However, in alternative designs, additionalstraps 170 can be used, such as two, three, four, five, or more.Multiple straps 170 can radiate from the central pushup portion 140 andthe longitudinal axis 150. In some embodiments, the straps 170 can beequally spaced apart about the axis 150.

Typically, although not limiting, rectangular containers (FIGS. 1-28B)may employ two or more even-numbered straps 170. The straps 170 can, insome embodiments, bisect the midpoint (i.e., the middle region) of therespective sidewall. Stated differently, the strap 170 can intersect therespective sidewall approximately midway between the adjacent sidewalls.If the sidewall portion 24 defines a different polygonal cross section(taken perpendicular to the axis 150), the straps 170 can similarlybisect the sidewalls.

Similarly, although not limiting, cylindrical containers (FIGS. 29A-30B)may employ three or more odd-numbered or even-numbered straps 170. Assuch, straps 170 can be disposed in a radial orientation such that eachof the plurality of straps 170 radiates from a central point of baseportion 28 to an external edge of the container 10 (e.g. adjacentsidewall portion 24). It should be noted, however, that although straps170 may radiate from a central point, that does not mean that each strap170 actually starts at the central point, but rather means that if acentral axis of each strap 170 was extended inwardly they wouldgenerally meet at a common center. The relationship of the number ofstraps used to radial strength of container 10 has shown an increasingradial strength with an increasing number of straps used (see FIG. 23B).

It should also be noted that strap 170 can be used in conjunction withthe aforementioned central pushup 140, which would thereby interruptstraps 170. However, alternatively, it should be noted that benefits ofthe present teachings may be realized using straps 170 without centralpushup 140.

As illustrated in the several figures, straps 170 can define any one ora number of shapes and sizes having assorted dimensional characteristicsand ranges. However, it has been found that particular strap designs canlead to improved vacuum absorption and container integrity. By way ofnon-limiting example, it has been found that straps 170 can define astrap plane or central axis 172 that is generally parallel to contactsurface 134 and/or a surface upon which container 10 sits, therebyresulting in a low strap angle. In other embodiments, strap plane/axis172 can be inclined relative to contact surface 135 and/or the surfaceupon which container 10 sits, thereby resulting in a high strap angle.In some embodiments, this inclined strap plane/axis 172 can be inclinedsuch that a lowest-most portion of inclined strap plane/axis 172 istoward an inbound or central area of container 10 and a highest-mostportion of inclined strap plane/axis 172 is toward an outbound orexternal area of container 10 (e.g. adjacent sidewall portion 24).Examples of such inclination can be seen in FIGS. 26B and 27B.

Low strap angles (e.g., FIGS. 1-4) provide base flexibility resulting inbase flex that displaces volume through upward deflection. This upwarddeflection will be enhanced under vertical load providing additionalvolume displacement, transitioning to positive pressure to maximizefilled capped topload. The volume displacement causes increased vacuumin the container 10. This complementary “co-flex base” technologyprovides volume displacement & filled capped topload performance therebyresulting in a “lightweight panel-less” container configuration formulti-serve applications. Conversely, a high strap angle (e.g., FIGS.26B and 27B) provides base rigidity resulting in a base that enhancesvertical and horizontal load bearing properties. Rectangular containerdesigns provide sufficient volume displacement. This complementary“rigid-base” technology provides enhanced handling properties onfill-lines and tray distribution offerings thereby resulting in a“lightweight tray capable” container configuration for multi-serveapplications.

By way of non-limiting example, it has been found that an inclinationangle α (FIG. 19) of strap plane/axis 172 of about 0 degrees to about 30degrees (i.e. strap angle) can provide improved performance. This strapangle α can be measured in a side cross-section take along strap planeor axis 172 relative to a horizontal reference plane or axis as shown inFIG. 19. However, it should be recognized that other strap angles may beused and/or the direction of inclination can be varied. The relationshipof inclination angle α to volume displacement of container 10 has shownan increasing volume displacement with a decreasing inclination angle α(see FIG. 33A).

With particular reference to FIGS. 26A-27B, it should be noted thatstrap 170 can further define or include a secondary contour or shapewhen viewed generally along strap plane or axis 172. That is, whenviewing from the side of the container 10, the strap 170 can define apeaked shape or trapezoid shape adjacent the sidewall portion 24 havinga raised central area and downwardly extending side surfaces (see FIGS.FIGS. 26B and 27B) as opposed to defining a generally flat, singleplane. The trapezoidally shaped portion can be planar also and disposedat a draft angle relative to a horizontal (imaginary) reference line.This draft angle can be between 0 degrees and 45 degrees. In someembodiments, this section of the strap 170 can have a triangular shapethat further provides improved vacuum response and structural integritywhile simultaneously permitting reduction in material weight and costs.By way of non-limiting example, it has been found that a peak 175 of thestrap 170 (FIGS. 19, 26B and 27B) can define a peak angle β (FIG. 19)relative to a vertical or perpendicular reference line in the range ofabout 0 degrees to 90 degrees (flat strap 170). In some embodiments,peak angle β can define a range of about 1 degree to about 45 degrees.However, it should be recognized that other angles may be used and/orthe direction and overall shape of strap 170 can be varied. Therelationship of peak angle β to volume displacement of container 10 hasshown an increasing volume displacement with a decreasing peak angle β(see FIG. 23C).

In some embodiments, as illustrated in FIGS. 1, 12, 16, 18, 20, 22, 24,29B, 30B, and 40-42, base portion 28 can further comprise one or moreribs 180 formed in (e.g., entirely within) or along strap 170, orbetween two straps 170. Ribs 180 can include an inwardly-directedchannel (recessed toward the interior of the container 10) oroutwardly-directed channel (projecting outward from the interior of thecontainer 10). Also, the rib 180 can be contained entirely within therespective strap 170 or can extend out of the respective strap 170 insome embodiments. The ribs 180 can serve to tune or otherwise modify thevacuum response characteristics of straps 170. In this way, ribs 180serve to modify the response profile of one or more straps 170. Withreference to the several figures, ribs 180 can follow one of a number ofpathways, such as a generally V-shaped pathway (FIGS. 29B, 30B) or alonglongitudinal axis 180 extending from the central longitudinal axis 150.In some embodiments, these pathways can define a pair of arcuatechannels 182 terminating at a central radius 184.

The plastic container 10 of the present disclosure is a blow molded,biaxially oriented container with a unitary construction from a singleor multi-layer material. A well-known stretch-molding, heat-settingprocess for making the one-piece plastic container 10 generally involvesthe manufacture of a preform (not shown) of a polyester material, suchas polyethylene terephthalate (PET), having a shape well known to thoseskilled in the art similar to a test-tube with a generally cylindricalcross section. An exemplary method of manufacturing the plasticcontainer 10 will be described in greater detail later.

Referring to FIG. 32, exemplary embodiments of a mold system 306 forblow molding the container 10 is illustrated. The mold system 306 can beemployed for the manufacture of container geometries, namely basegeometries, that could not be previously made. As illustrated in FIG.32, in some embodiments, the mold system 306 can comprise a base system310 disposed in operably connection with a sidewall system 320. Basesystem 310 can be configured for forming generally an entire portion ofbase portion 28 of container 10 and extends radially and upward until atransition to sidewall portion 24. Base system 310, in some embodiments,can maintain a temperature that is different from sidewall system320—either hotter or colder than sidewall system 320. This canfacilitate formation of container 10 to speed up or slow down therelative formation of the base portion 28 of container 10 duringmolding.

In some embodiments, base system 310 can comprise a lower pressurecylinder to extend and retract a push up member 323 (shown in phantom inFIG. 32). The push up member 32 can be used to extend or otherwisestretch central pushup 140 axially toward the interior of the container10. As seen in FIG. 32, push up member 322 can be centrally disposed inbase system 310. Also, the push up member 322 can have a retractedposition, wherein the push up member 322 is close to flush withsurrounding portions of the base system 310, and an extended position(shown in phantom), wherein the push up member 322 can extend away fromsurrounding portions of the base system 310. In the extended position,the push up member 322 can engage the preform during forming and urgepreform upward (e.g. inwardly) to form central pushup 140. Also,following formation of central pushup 140, push up member 322 can beretracted to permit demolding of the final container 10 from the mold.In some additional embodiments, push up member 322 of base system 310can be paired with a counter stretch rod, if desired.

An exemplary blow molding method of forming the container 10 will now bedescribed. A preform version of container 10 includes a support ring,which may be used to carry or orient the preform through and at variousstages of manufacture. For example, the preform may be carried by thesupport ring, the support ring may be used to aid in positioning thepreform in a mold cavity 321 (FIG. 32), or the support ring may be usedto carry an intermediate container once molded. At the outset, thepreform may be placed into the mold cavity 321 such that the supportring is captured at an upper end of the mold cavity 321. In general, themold cavity has an interior surface corresponding to a desired outerprofile of the blown container. More specifically, the mold cavityaccording to the present teachings defines a body forming region, anoptional moil forming region and an optional opening forming region.Once the resultant structure (hereinafter referred to as an intermediatecontainer) has been formed, any moil created by the moil forming regionmay be severed and discarded. It should be appreciated that the use of amoil forming region and/or opening forming region are not necessarily inall forming methods.

In one example, a machine (not illustrated) places the preform heated toa temperature between approximately 190° F. to 250° F. (approximately88° C. to 121° C.) into the mold cavity. The mold cavity may be heatedto a temperature between approximately 250° F. to 350° F. (approximately121° C. to 177° C.). A stretch rod apparatus (not illustrated) stretchesor extends the heated preform within the mold cavity to a lengthapproximately that of the intermediate container thereby molecularlyorienting the polyester material in an axial direction generallycorresponding with the central longitudinal axis of the container 10.While the stretch rod extends the preform, air having a pressure between300 PSI to 600 PSI (2.07 MPa to 4.14 MPa) assists in extending thepreform in the axial direction and in expanding the preform in acircumferential or hoop direction thereby substantially conforming thepolyester material to the shape of the mold cavity and furthermolecularly orienting the polyester material in a direction generallyperpendicular to the axial direction, thus establishing the biaxialmolecular orientation of the polyester material in most of theintermediate container. The pressurized air holds the mostly biaxialmolecularly oriented polyester material against the mold cavity for aperiod of approximately two (2) to five (5) seconds before removal ofthe intermediate container from the mold cavity. This process is knownas heat setting and results in a heat-resistant container suitable forfilling with a product at high temperatures.

Alternatively, other manufacturing methods, such as for example,extrusion blow molding, one step injection stretch blow molding andinjection blow molding, using other conventional materials including,for example, high density polyethylene, polypropylene, polyethylenenaphthalate (PEN), a PET/PEN blend or copolymer, and various multilayerstructures may be suitable for the manufacture of plastic container 10.Those having ordinary skill in the art will readily know and understandplastic container manufacturing method alternatives.

With additional reference to FIGS. 40-45, the container 10 isillustrated as a generally round container with a generally round base30. Although the container 10 and the base 30 are generally illustratedin FIGS. 40-45 as being round, the container 10 and the base 30 can haveany suitable shape or size. For example, the container 10 can have anyof the shapes described and/or illustrated above, including, but notlimited to, the following: rectangular, triangular, pentagonal,hexagonal, octagonal, polygonal, or square.

The base 30 includes lightweight base configuration 100, which generallyincludes straps 170, central pushup portion 140, and ribs 180. Thestraps 170 extend generally radially from the central longitudinal axis150 away from the central pushup portion 140 to the sidewall portion124. Each one of the straps 170 is spaced apart about the base 30. Thestraps 170 can be spaced apart at any suitable interval, such as agenerally uniform interval as illustrated in FIGS. 40-42, for example.Any suitable number of the straps 170 can be included, such as five asillustrated or seven. Generally, the greater the diameter of the base30, the more straps 170 that can be included.

Each one of the straps 170 extends along the strap plane/axis 172thereof and is thus an elongated strap. The straps 170 are illustratedas each having a width that generally increases along a length thereof,such that each strap is widest at the sidewall portion 24 and mostnarrow proximate to the central longitudinal axis 150. In other words,the strap surface 173 extends further from either side of the strapplane/axis 172 at the sidewall portion 24 as compared to proximate tothe central longitudinal axis 150.

Each strap 170 generally includes a first end 176 and a second end 178,which are at opposite ends of each strap 170 along the strap plane/axis172 thereof. The first end 176 is proximate to the longitudinal axis 150and the second end is at the sidewall portion 24. Each strap 170 extendslinearly from the first end 176 to the second end 178, such as linearlyalong the strap plane/axis 172 extending along the strap surface 173from the first end 176 to the second end 178 at the peak 175. Each strap170 is generally inclined along the strap plane/axis 172 thereof fromthe first end 176 to the second end 178, such that the first end 176 isgenerally at the contact surface/foot surface 134 of the base 30 and thesecond end 178 is at the peak 175. Therefore, the second end 178 isfurther recessed into the base 30 as compared to the first end 176,which may not be recessed into the base 30 at all. Although the straps170 are illustrated as generally being inclined or sloped in thismanner, the straps 170 need not be inclined, and thus the strapplane/axis 172 may extend linearly such that the strap plane/axis 172 isperpendicular to, or substantially perpendicular to, the centrallongitudinal axis 150 along its entire length or a substantial portionthereof.

The base 30 further includes a plurality of the ribs 180, which asillustrated in the container 10 of FIGS. 40-45 are spaced apart from thestraps 170. Each rib 180 is generally elongated and extends generallyradially from the central longitudinal axis 150 along a rib longitudinalaxis 190 of each rib 180. Each rib 180 extends to the sidewall portion24 from any suitable position along the base 30 between the centrallongitudinal axis 150 and the sidewall 30. One or more of the ribs 180can be between two of the straps 170. For example and as illustrated,only one of the ribs 180 can be between two of the straps 170, and canbe equidistant between the two straps 170. Any suitable number of ribs180 can be included, such as five as illustrated. The number of ribs 180can generally correspond to the number of straps 170, such that a singlerib 180 is between two of the straps 170.

With reference to FIG. 43, the straps 170 extend linearly and are angledsuch that relative to a base surface 192 that the container 10 may beseated upon, at the inclined strap plane/axis 172 the strap surface 173is at an angle α from the surface 192. The angle α can be any suitableangle such as, for example, from about 0° to about 30°, from about 5° toabout 20°, about 10°, or 10°. With respect to the central longitudinalaxis 150, the straps 170 can be arranged at an angle β, which ismeasured between the central longitudinal axis 150 and the inclinedstrap plane/axis 172. The angle β can be any suitable angle, such as inthe range of about 0° to about 90°, about 45° to about 85°, about 80°,or 80°.

With continued reference to FIG. 43, the central pushup portion 140includes a top offset surface 194 at the top surface 146 and a bottomoffset surface 196 opposite to the top offset surface 194. The topoffset surface 194 is recessed within the top surface 146, and thebottom offset surface 196 protrudes from a bottom surface 200 of thecentral pushup portion 140, which is opposite to the top surface 146.The central pushup portion 140 further includes a flange 198 defined bythe side surfaces 148 of the central pushup portion 140. The sidesurfaces 148 are illustrated as generally curving away from the centrallongitudinal axis 150, but can have any other suitable shape orconfiguration as described above, such as in conjunction with FIG. 34,which illustrates side surfaces 148 having concave, convex, andgenerally planar surfaces.

With reference to FIGS. 44 and 45, the lightweight base configuration100 is configured to move, such as by flexing, in a variety of differentdirections in order to enhance durability, structural integrity,resistance to undesirable deformation, and usefulness of the container10, such as when the container 10 is subject to increased vacuumpressures during cooling of hot filled contents thereof. For example andas illustrated in FIG. 44, the central pushup portion 140 is configuredto move along the central longitudinal axis 150, and remain centered onthe central longitudinal axis 150 as the central pushup portion 140moves along the central longitudinal axis 150. The central pushupportion 140 is arranged such that the central longitudinal axis 150extends through the top offset surface 194, the bottom offset surface196, and generally an axial center of the top surface 146.

As illustrated in FIG. 44, the central pushup portion 140 can flex alongthe central longitudinal axis 150 towards the finish 20 to position140′, with the side surface 148 flexing to 148′. As the central pushupportion 140 flexes along the central longitudinal axis 150 towards thefinish 20, the straps 170 also flex towards the finish 20, such as tothe position at 170′ of FIG. 44. Relative to a line 210 extending fromabout the outward strap radius 202 parallel to base surface 192 thatcontainer 10 may be seated on, and perpendicular to axis 150, the straps170 flex across an angle α up to the line 210 and flex across angle β upand away from the line 210. The angles α and β are the same or generallythe same.

As the straps 170 move to the position at 170′, an outward strap radius202 will generally decrease and move to position 202′. The outward strapradius 202/202′ is generally measured at the smallest radius where thestraps 170 transition to the sidewall portion 24 at an interior of thecontainer 10. As illustrated in FIG. 46, as the volume displaced of thecontainer 10 increases, the outward strap radius 202 generally decreasesto 202′. At 3% volume displaced, for example, the outward strap radius202 generally decreases from about 10% to about 40%, such as 25% orabout 25% of the original; or to within a range of about 0.9 times toabout 0.6 times the original, such as 0.75 times or about 0.75 times theoriginal. The degree to which the outward strap radius 202 decreaseswill depend on the size and the composition of the container 10, as wellas on the contents thereof and the number of straps 170 present. Forexample, the greater the number of straps 170 present, the more that theoutward strap radius 202 will decrease.

With reference to FIG. 45, as the central pushup portion 140 moves alongthe central longitudinal axis 150 towards the finish 20, a baseclearance Cb will increase a distance Cb′, thereby making the overallbase clearance Cb+Cb′. With respect to FIG. 47 for example, as thevolume displaced percentage increases, the distance Cb′ will alsoincrease. At 3% volume displaced for example, the base clearance willincrease anywhere from about 3 mm to about 7 mm. In other words, thedistance Cb′ will increase to within a range of from about 3 mm to about7 mm. The distance that the base clearance increases, which isidentified in FIG. 45 as Cb′, depends on the size and the composition ofthe container 10, as well as on the contents thereof and the number ofstraps 170 present. For example, the greater the number of straps 170present, the more that the base clearance will increase, and the greaterthat the distance Cb′ will be.

As also illustrated in FIG. 45, as the central pushup portion 140 movestowards the finish 20, the contact/foot surface 134 moves towards thefinish 20 to position 134′, thus decreasing standing base radius Rsb toRsb′. The standing base radius is generally measured from the centrallongitudinal axis 150 to a point where the contact/foot surface 134makes contact with surface 192. With reference to FIG. 48, as the volumedisplaced percentage increases, the standing base radius will generallydecrease from Rsb to Rsb′. At 3% volume displacement, for example, thestanding base radius will generally decrease to Rsb′ within a range offrom about 28 mm to about 40 mm. Again, the distance that the standingbase radius decreases will depend on the size and composition of thecontainer, the contents thereof, and the number of straps 170 present.

With reference to FIG. 49, as the volume displaced of the container 10increases and the side surface 148 flexes to 148′ as illustrated in FIG.45, an inward foot radius 149 of the base configuration 100 increases asmeasured at about a midway point along the curved side surface 148. At3% volume displacement, for example, the inward foot radius can increaseabout 1.1 times to about 2.0 times the original before displacement,such as 1.5 times or about 1.5 times the original. The decrease in theoutward strap radius and the increase in the inward foot radius aredirectly proportional. For example, the inward foot radius increases adistance that is about 1.2 times to about 3.3 times, or about 2 times,the distance that the outward strap radius decreases. Thus, if theinward foot radius increases about 2 times the distance that outwardstrap radius decreases, then the outward strap radius will decrease 10%or about 10%, and the inward foot radius will increase 20% or about 20%.Any suitable relationship can be established between the outward (orouter) strap radius and the inward (or inner) foot radius. Withreference to FIG. 1 for example, the relationship between the outwardstrap radius and the inward foot radius can be set at any point in theillustrated box.

As the volume displaced of the container increases, the width Ws of eachstrap 170 (see FIG. 40 for example), decreases. The width can bemeasured between any suitable points of each strap 170. For example, thewidth of each strap 170 can be measured between two points that are onopposite sides of the strap plane/axis 172, furthest from thelongitudinal axis 150, and configured to rest on planar base surface 192when the container 20 is seated on the planar surface 192. As the widthWs of each strap 170 decreases, the feet 134 between the straps 170 movecloser together, thus decreasing a foot separation distance between thefeet 134. With reference to FIG. 50, as the volume displaced increases,the foot separation distance also decreases. At a volume displacement ofabout 3%, the foot separation distance will decrease about 5% to about20%, such as about 10% to about 17%, such as about 12.5%. The width Wsof the straps 170 is effectively the separation distance between thestraps 170, and thus the width Ws of the straps 170 will decrease thesame amount as the separation distance.

With additional reference to FIGS. 52A-52D, another configuration of thecontainer 10 according to the present teachings is illustrated. FIG. 52Aillustrates the container 10 in an as-blown, pre-filled configuration.FIG. 52B illustrates the container 10 after being hot-filled andsubsequently cooled, with the as-blown position shown at AB. FIG. 52Cillustrates the container 10 subject to top load pressure, with theas-blown position shown at AB. FIG. 52D illustrates the container 10subject to additional top load pressure, with the as-blown positionshown at AB. The container 10 of FIGS. 52A-52D includes the generallyround base portion 30 and the light base configuration 100 describedabove. Thus, the container 10 of FIGS. 52A-52D includes the straps 170and the central pushup portion 140, and may include the ribs 180 aswell.

The main body portion 12 includes the sidewall 24, which extends to thebase portion 30 of the container 10. The sidewall 24 defines an internalvolume 326 of the container 10 at an interior surface thereof. Thesidewall 24 may be tapered inward towards the longitudinal axis 150 atone or more areas of the sidewall 24 in order to define recesses or ribs350 at an exterior surface of the sidewall 32, as well as an inwardlytapered portion 352 between the ribs 350 and the shoulder portion 22. Asillustrated, the sidewall 24 defines five recesses or ribs 350 a-350 e.However, any suitable number of recesses or ribs 350 can be defined. Theribs 350 can have any suitable external diameter, which may vary amongstthe different ribs 350.

In response to an internal vacuum, the ribs 350 can articulate about thesidewall 24 to arrive at a vacuum absorbed position, as illustrated inFIG. 52B for example. Thus, the ribs 350 can be vacuum ribs. The ribs350 can also provide the container 10 with reinforcement features,thereby providing the container 10 with improved structural integrityand stability. Larger ribs, such as rib 350 a which has a largervertical height and is recessed deeper in the sidewall 24 relative toother ribs 350, will have a greater vacuum response. Smaller ribs, suchas ribs 350 b, 350 c, and 350 e, will provide the container withimproved structural integrity.

The combination of base portion 30, which as described above is a vacuumbase portion 30, and the horizontal ribs 350 allows the container 10 toreach a state of hydraulic charge up when a top load force is appliedafter the container 10 is filled, as illustrated in FIGS. 52C and 52Dfor example, which allows the container 10 to maintain its basic shape.This movement of the base portion 30 caused by top load force isconstrained by the standing surface, and the horizontal ribs 350 beginto collapse, thereby causing filled internal fluid to approach anincompressible state. At this point, the internal fluid resists furthercompression and the container 10 behaves similar to a hydrauliccylinder, while maintaining the basic shape of the container 10.

More specifically, in the as-blown, prefilled configuration AB of FIG.52A, the container 10 stands upright while resting on diaphragm 354, andvolume and pressure are zero or generally zero, thereby providing thecontainer 10 in phase 1. FIG. 53 is a graph of base volume change versuspressure, and FIG. 54 is a graph of filled, capped, and cooled top loadversus displacement of an exemplary container 10 according to thepresent teachings. The various phases described herein are illustratedin FIGS. 53 and 54.

With reference to FIG. 52B, after the container 10 is hot-filled andcooled, the base portion 30 is pulled up towards an upper end 356 of thecontainer 10 due to internal vacuum. The upper end 356 is at the finish20 and is opposite to a lower end 358 of the container 10 at the baseportion 30. Overall height of the container 10 is reduced (compare thecontainer 10 in the as-blown position AB), and the container 10 issupported upright at an outer portion (or standing surface) of the baseportion 30 to provide the container 10 at phase 2. With reference toFIG. 52C, application of top load urges the base portion 30 to theoriginal as-blown position of FIG. 52A, and the internal vacuum crossesover to positive internal pressure, thereby providing phase 3. FIG. 52Dillustrates phase 4 and an increase in top load, which returns the baseportion 30 substantially to the original as-blown position of FIG. 52Aand phase 1. The base portion 30 is constrained by the standing surfacethereof, the ribs 350 collapse causing further reduction in internalvolume of the container 10, and a hydraulic spike in internal pressureadvantageously facilitates very high top load capability.

FIGS. 55-57 illustrate pressure-volume characteristics under vacuum andfilled capped cooled top load of an exemplary container 10 according tothe present teachings. Specifically, FIG. 55 illustrates containervolume change versus pressure. FIG. 56 illustrates body volume changeversus pressure. FIG. 57 illustrates the base volume change versuspressure. From FIG. 57, it is clear that the base 30 is flexible undervacuum and significantly stiffer under top load, which is a desiredcharacteristic for good vacuum and filled capped cooled top load. FIG.56 demonstrates that under top load the volume of the body and ribs 350continuously decreases, leading to increased pressure. The ribs 350 aresuitable for allowing displacement to increase as top load increasesbecause the ribs 350 are axially flexible (i.e., can be axiallycompressed to lead to pressure charge-up) and radially stiff to maintainpressure. Therefore, combination of the base 30 and ribs 350 provides anadvantageous configuration for improved vacuum and top load responses.

The features described in conjunction with the container 10 illustratedin FIGS. 52A-52D can be included with any of the containers 10 accordingto the present teachings. For example, any of the containers 10described herein can include any suitable number of the ribs 350, suchas five ribs 350 a-350 e. Furthermore, any of the containers 10according to the present teachings can exhibit the performancecharacteristics set forth in the graphs at FIGS. 53-57, such as byproviding the containers 10 with the ribs 350 and the base portion 30including the straps 170 and central pushup 140, and optionally the ribs180.

The containers disclosed in accordance with the present teachings,particularly the bases thereof, can have any suitable dimensions. Forexample and with reference to FIGS. 58A and 58B, base 30 of lightweightbase configuration 100, which is a generally round base, can have atotal projected area of foot surface 134/134′ that is 2 times greaterthan the projected surface area of strap surface 170 as illustrated inFIG. 58A. For example, the strap area 410A can have a total projectedarea of 11.7 cm². The total projected area of foot area 410B can be 23.8cm². In other embodiments shown in FIGS. 60A-60E, the base 30 can have atotal projected area of foot surface 134/134′ that is 2 to 4.8 timesgreater than the projected surface area of strap surface 170.

Each one of the straps 170 can extend outwards from the central pushupportion 140 at an angle 412A of about 24°, which provides the base 30with a total strap angle of 120° (24°×5). The foot area 412B can extendfrom the central pushup portion 140 at an angle about 48°, whichprovides the base 30 with a total foot angle of 240° (40°×5). The base30 thus has a foot angle 412B that is 2 times greater than the strapangle 412A. In other embodiments shown in FIGS. 60A-60E, the base 30 canhave a foot angle 412B that is between 2 to 5 times the strap angle412A.

The base 30 can have a total projected outside perimeter 414A of straps170 of 76 mm, and a total projected outside perimeter 414B of the feet134 of 155 mm. Thus the ratio of the total projected outer perimeters414A and 414B is 1:2. In other embodiments shown in FIGS. 60A-60E, theouter perimeter 414B of the feet 134 can be 0.4 to 3 times the outerperimeter 414A of the straps 170.

With respect to the inner perimeter, the total projected inner perimeter416A of straps 170 can be 31 mm, and the total projected insideperimeter 416B of the feet 134 can be 63 mm. Thus the ratio of the totalprojected inside perimeters 416A to 416B is 1:2. In other embodimentsshown in FIGS. 60A-60E, total inside perimeter 416B of the feet 134 canbe 2 to 3 times greater than the total inside perimeter 416 A of thestraps 170.

With continued reference to FIG. 58A and additional reference to FIG.58B, the base 30 can have a strap angle 420 of +5 degrees as measuredbetween an innermost surface of strap 170 and surface 192, which extendsperpendicular to central longitudinal axis 150. The base 30 can have afoot angle 430 of −15 degrees, as measured between an innermost surfaceof inner/contact foot surface 134′, and surface 192. The differentbetween the strap angle 420 and the foot angle 430 can be 20°, or withinthe range of 12° to 27° as show in other embodiments in FIGS. 60A-60E.

With reference to FIGS. 59A and 59B, generally rectangular base 30 canhave a total projected strap area 510A of 27.5 cm², and a totalprojected foot area 510B of 56.5 cm². The rectangular base 30 can havestrap angles 512A of 43°, and strap angles 512A′ of 56°, for a totalstrap angle of 198° (43°+43°+56°+) 56°. The rectangular base 30 can havefoot angles 512B of 40°, for a total foot angle of 160° (40°×4). Thusthe ratio of the total strap angles to total foot angles is 1:8. Thegenerally rectangular base 30 of FIGS. 59A and 59B can have an outerstrap perimeter 514A of 147 mm, and an outer foot perimeter 514B of 218mm. Thus the ratio of the outer strap perimeter 514A to outer footperimeter 514B is 1:1.5. The rectangular base 30 can have a rectangularinner strap perimeter 516A of 37 mm, and an inner foot perimeter 516B of95 mm. Thus the ratio of the inner strap perimeter 516A to inner footperimeter 516B can be 2:5. The rectangular base 30 can have a strapangle 520 of +7° (FIG. 59B), and a foot angle 530 of −5° (FIG. 59C). Thedifference between the strap angle 520 and the foot angle 530 can be12°. With reference to FIG. 59D, pushup major diameter 550 can be 40% to50% greater than pushup minor diameter.

For both the round base 30 of FIGS. 58A and 58B, and the generallyrectangular base 30 of FIGS. 59A-59D, the foot angle range (430, 530) is−4° to −15°. The strap angle range (420, 520) is +5° to +23°. The deltarange of the axial strap to foot angle relationship is 12°-27°.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention. Individual elements or features ofa particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the invention, and all such modificationsare intended to be included within the scope of the invention.

What is claimed is:
 1. A container defining a longitudinal axis and atransverse direction that is transverse with respect to the longitudinalaxis, the container comprising: a finish; a sidewall portion extendingfrom the finish; a plurality of ribs defined by the sidewall portion; abase portion extending from the sidewall portion and enclosing thesidewall portion to form a volume therein for retaining a commodity, thebase portion having a plurality of footed contact surfaces forsupporting the container; and a plurality of straps extending radiallyalong the base portion away from the longitudinal axis in the transversedirection, each one of the straps defining a strap surface that iscloser to the finish than the plurality of footed contact surfaces;wherein: the plurality of ribs and the base portion are configured toplace the container in a state of hydraulic charge-up when top load isapplied to the container after the container is filled and closed with aclosure coupled to the finish; the container is made of a polymericmaterial; the base portion includes a central pushup portion at an axialcenter thereof, the longitudinal axis extends through the central pushupportion; an outward strap radius defined by the base portion decreaseswhen the container is subject to volume displacement causing increasedvacuum; an inward foot radius defined by the base portion increases whenthe container is subject to volume displacement causing increasedvacuum, the inward foot radius is inward relative to the plurality offooted contact surfaces of the container and is along a curved sidesurface between the plurality of footed contact surfaces and the centralpushup portion; a standing base radius defined by the base portiondecreases when the container is subject to volume displacement causingincreased volume; and a total projected area of the plurality of footedcontact surfaces is at least twice the size of a total projected area ofthe plurality of straps.
 2. The container of claim 1, wherein: the baseportion is rectangular and each one of the plurality of straps is angled+7° relative to a planar surface for supporting the container upright;and each one of the plurality of footed contact surfaces is angled −5°relative to the planar surface for supporting the container upright. 3.The container of claim 1, wherein the base is rectangular and theplurality of footed contact surfaces extend outward from the centralpushup portion at a total angle that is eight times as large as a totalangle that the plurality of straps extend outward from the centralpushup portion.
 4. The container of claim 1, wherein: the base isrectangular and each one of the plurality of straps extends outward fromthe central pushup portion at an angle of 43° or 56°; and each one ofthe plurality of footed contact surfaces extends outward from thecentral pushup portion at an angle of 40°.
 5. The container of claim 1,wherein the base is rectangular and each one of the plurality of footedcontact surfaces has an outer perimeter that is 1.5 times greater thanan outer perimeter of each one of the plurality of straps.
 6. Thecontainer of claim 1, wherein: the base is rectangular and each one ofthe plurality of straps has an outer perimeter of 147 mm; and each oneof the plurality of footed contact surfaces has an outer perimeter of218 mm.
 7. The container of claim 1, wherein the base portion isrectangular and each one of the plurality of footed contact surfaces hasan inner perimeter that is 2.5 times the size of an inner perimeter ofeach one of the plurality of straps.
 8. The container of claim 1,wherein: the base portion is rectangular and each one of the pluralityof straps has an inner perimeter of 37 mm; and each one of the pluralityof footed contact surfaces has an inner perimeter of 95 mm.